16hVaughn McClure, ESPN Staff Writer0SharesEmailPrintCommentFLOWERY BRANCH, Ga. -- Atlanta Falcons starting free safety Ricardo Allen is recovering from a medial collateral ligament sprain in his left knee, according to multiple sources, but the injury is not believed to be severe.

Allen, who was limited in practice this week, won't play against the Houston Texans. There's a chance his sprained MCL will keep him sidelined just a couple of weeks. The lowest grade of MCL sprain calls for a one-to-two-week recovery.

Allen did not talk about the injury when approached Friday. He wore a compression sock to protect the knee, which he injured during the second quarter of Sunday's 39-28 win over the Cowboys. The fact that Allen returned to the game and ended up playing 45 of 53 defensive snaps might have been an indication that he'll be back sooner than later.

Ricardo Allen managed to play 45 of the Falcons' 53 defensive snaps against Dallas despite suffering an MCL sprain in the first half. AP Photo/Brynn AndersonUndrafted rookie Robenson Therezie, who has spelled Allen the past two games, will likely get the first chance to replace Allen. Kemal Ishmael is another option at free safety.

"Obviously it's confidence in Lac," strong safety William Moore said of Therezie, nicknamed "Cadillac." "Obviously, the coaching staff has confidence that he can get the job done, and so do I. He's had a tremendous training camp. You know the NFL, man: next man up.

"[Ricardo] has worked his tail off to get to this point. You know, it's unfortunate when you get injuries like that. ... I don't know the status of his injury; how long or whatever. Just to Therezie, just go out there and communicate and just study your playbook like no other this week, man. It's no pressure.''

Therezie, who did not play in the season opener, had 18 defensive snaps over the past two games. His first action came against the New York Giants in Week 2 in place of Allen, who was benched to shake off giving up a 67-yard touchdown to Odell Beckham Jr. off a quick slant.

Falcons coach Dan Quinn talked about Therezie filling the void.

"As you guys know, he's someone that we've been really excited about," Quinn said. "The opportunity for him to come in and play the middle of the field safety -- and we've also got Ishmael working there -- so, yeah, we're really excited for him. He's had a terrific offseason.

"I think when you play in the middle of the field, the communication that has to happen. You have such a field of view -- you can say I can get the communication over to the safety, I can get it down to the nickel -- so that's where were really hoping for him. Allow that communication to come out."

Therezie has to be sound if he's the last line of defense, and the Falcons fully expect the Texans to take deep shots with speedy receivers, led by DeAndre Hopkins, who ran a 4.41 in the 40-yard dash coming out of Clemson. Hopkins had 20 catches of 20-plus yards last season and a 76-yard touchdown. His tag-team partner, veteran Nate Washington, had an 80-yard touchdown last season and had a 48-yard reception from Ryan Mallett this year against Carolina.